Contact imaging sensor head for computed radiography

Abstract

A scan head design uses 1:1 (one-to-one) imaging micro-lens arrays to transfer the object plane X-ray image from a CR-plate onto a linear photosensor. The scan-head includes a housing having therein, an array of red light emitting diodes (LEDs), a microlens array, and a sensor. The housing faces the CR-plate and the scan-head is translated across the CR-plate to read out the X-ray image therein. The scan head is compact and provides for improved spatial resolution and reduced power requirements.

The invention claimed is: 
     
       1. A system for readout-scanning of a previously exposed photostimulable storage phosphor plate containing an X-ray image comprising:
 an array of light emitting diodes (LEDs) oriented at a predetermined angle to the exposed photostimulable storage phosphor plate to illuminate directly a first predetermined portion of the exposed photostimulable storage phosphor plate; and 
 an imaging array for receiving image photons emitted directly from the exposed first predetermined portion of the photostimulable storage phosphor plate responsive to the illumination from the array of light emitting diodes (LEDs), wherein the imaging array forms the X-ray image on a sensor, and 
 further wherein, the array of light emitting diodes (LEDs), the imaging array and the sensor are located on a same side of the exposed photostimulable storage phosphor plate. 
 
     
     
       2. The system of  claim 1 , further comprising: one or more filters located between the imaging array and the sensor. 
     
     
       3. The system of  claim 1 , wherein the predetermined angle is less than 45 degrees. 
     
     
       4. The system of  claim 1 , wherein light emitted from the array of light emitting diodes (LEDs) encounters a reflective surface. 
     
     
       5. The system of  claim 1 , wherein the sensor is a CMOS sensor. 
     
     
       6. The system of  claim 1 , wherein the imaging array is a microlens array. 
     
     
       7. The system of  claim 1 , wherein a system height is equal to or less than 13 mm. 
     
     
       8. The system of  claim 1 , wherein the array of light emitting diodes (LEDs) comprises surface-mount LED devices with individual dome lenses for focusing LED emitted light in a forward direction. 
     
     
       9. The system of  claim 8 , wherein individual LEDs have a spacing of approximately 1.0 mm. 
     
     
       10. A process for readout-scanning of a previously exposed photostimulable storage phosphor plate containing an X-ray image by a scan-head, the process comprising:
 orienting an array of light emitting diodes (LEDs) of the scan-head at a predetermined angle to the exposed photostimulable storage phosphor plate at a first time T 1 ; 
 focusing light emitted from the LEDs at a line on the exposed photostimulable storage phosphor plate resulting in a stimulated emission line-source of image photons therefrom, wherein the focused light directly illuminates a first predetermined portion of the exposed photostimulable storage phosphor plate; and 
 receiving at an imaging array of the scan-head the image photons emitted directly from the exposed first predetermined portion of the photostimulable storage phosphor plate responsive to the illumination from the array of light emitting diodes (LEDs), and forming the X-ray image on a sensor, wherein, the array of light emitting diodes (LEDs), the imaging array and the sensor are located on a same side of the exposed photostimulable storage phosphor plate. 
 
     
     
       11. The process according to  claim 10 , further comprising:
 reflecting the light emitted from the LEDs at a first reflective surface of the scan-head. 
 
     
     
       12. The process according to  claim 10 , further comprising:
 filtering the light emitted from the LEDs by at least a first filter of the scan-head. 
 
     
     
       13. The process according to  claim 10 , further comprising:
 translating the scan head and repeating the orienting, focusing, receiving and forming at times T 2  to T x  until the exposed photostimulable storage phosphor plate has been read. 
 
     
     
       14. A scan-head for readout-scanning of a previously exposed photostimulable storage phosphor plate containing an X-ray image comprising:
 a housing including therein,
 an array of light emitting diodes (LEDs), 
 an imaging array, and 
 a sensor; 
 
 wherein the scan-head is translatable across the previously exposed photostimulable storage phosphor plate to read out the X-ray image therein; and 
 further wherein the array of light emitting diodes is oriented at a predetermined angle to the exposed photostimulable storage phosphor plate to illuminate directly a first predetermined portion of the exposed photostimulable storage phosphor plate; and 
 further wherein the imaging array receives image photons emitted directly from the exposed first predetermined portion of the photostimulable storage phosphor plate responsive to the illumination from the array of light emitting diodes (LEDs) and forms the X-ray image on the sensor from at least the first predetermined portion of the exposed photostimulable storage phosphor plate, wherein, the array of light emitting diodes (LEDs), the imaging array and the sensor are located on a same side of the exposed photostimulable storage phosphor plate. 
 
     
     
       15. The scan-head according to  claim 14 , wherein the housing has dimensions equal to or less than a height of 13 mm and a width of 24 mm. 
     
     
       16. The scan-head of  claim 14 , further comprising: one or more filters located between the imaging array and the sensor. 
     
     
       17. The scan-head of  claim 14 , wherein light emitted from the array of light emitting diodes (LEDs) encounters a reflective surface. 
     
     
       18. The scan-head of  claim 14 , wherein the predetermined angle is less than 45 degrees. 
     
     
       19. The scan-head of  claim 14 , wherein the sensor is a CMOS sensor. 
     
     
       20. The scan-head of  claim 14 , wherein the imaging array is a mircolens array. 
     
     
       21. The scan-head of  claim 14 , wherein the array of light emitting diodes comprises surface-mount LED devices with individual dome lenses for focusing LED emitted light in a forward direction. 
     
     
       22. The scan-head of  claim 21 , wherein the LEDs have a spacing of approximately 1.0 mm. 
     
     
       23. The scan-head of  claim 21 , wherein the scan-head focuses the LED emitted light at a line on the exposed photostimulable storage phosphor plate resulting in a stimulated emission line-source of image photons therefrom.